data_global
_chemical_name_mineral 'Quartz'
loop_
_publ_author_name
'Hazen R M'
'Finger L W'
'Hemley R J'
'Mao H K'
_journal_name_full 'Solid State Communications'
_journal_volume 72 
_journal_year 1989
_journal_page_first 507
_journal_page_last 511
_publ_section_title
;
 High-pressure crystal chemistry and amorphization of alpha-quartz
 Sample: P = 5.1 GPa
;
_database_code_amcsd 0015464
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Si O2'
_cell_length_a 4.705
_cell_length_b 4.705
_cell_length_c 5.250
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 120
_cell_volume 100.649
_exptl_crystal_density_diffrn      2.974
_symmetry_space_group_name_H-M 'P 31 2 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  'y,x,-z'
  '-y,x-y,1/3+z'
  '-x,-x+y,1/3-z'
  '-x+y,-x,2/3+z'
  'x-y,-y,2/3-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Si   0.45320   0.00000   0.33333   0.00646
O   0.39300   0.28810   0.23400   0.01089